Count Sen. Joe Lieberman as a “no” on President Barack Obama’s tax plan.

The Connecticut independent has just decided he will vote against the plan, saying it’s “not what we need now,” especially since it stands virtually no chance of becoming law before November.

“It’s not that I don’t think we ought to raise taxes on people that make more money,” Lieberman told POLITICO. “To me, we ought to be focused on achieving a bipartisan, long-term debt elimination agreement. And that tax reform and tax increases would be part of it. I don’t want to pick it off piece by piece.”

While the moderate Lieberman’s opposition is by no means a surprise, it could complicate Senate Majority Leader Harry Reid’s efforts to ensure there are 51 votes for the president’s plan. Anything short of a simple majority of Senate support would be seen as a blow to Obama in the heat of his reelection bid.

Still, Lieberman allowed Reid an easier path to reach that 51-vote threshold. If the vote is on procedural grounds to break a GOP-led filibuster, which would require 60 votes, Lieberman said he could potentially vote to advance the bill so it can receive an up-or-down vote on the merits. He said he has not made up his mind on that possibility.

But if the party leaders agree to hold a vote on the merits of the plan with a 60-vote or simple-majority threshold, Reid and the White House may need to scramble to prevent any more defections in the 53-member Senate Democratic Caucus.

Reid, however, seems confident that he can pass the plan with 51 votes and keep the GOP plan under 50 votes. On the floor Wednesday evening, Reid tried to set up votes asking for a simple-majority threshold on both plans, but Senate Minority Leader Mitch McConnell balked at the idea, saying he had yet to see a Democratic proposal on paper.

Democrats believed that McConnell was unsure he could block the Obama plan in the Senate if only 51 votes were needed to approve it. Passing the plan in the Senate would give the president fresh ammunition in the campaign even though it would certainly be rejected by the GOP-led House.

It will be up to Reid and McConnell to hammer out an agreement setting votes on the president’s tax cut plan limited at income earned at the $250,000 level and the GOP’s proposal to extend all of the Bush-era tax cuts, including for high earners. Earlier in the day Wednesday, McConnell tried to set votes immediately on both proposals, but Reid objected, prompting GOP accusations that Democrats were avoiding quick votes because of internal divisions.

Reid later said there would be votes on the tax plans before the Senate’s August recess, giving each side fodder for the fall campaigns.

Democrats are generally united behind the president’s plan. But some senators, particularly ones up for reelection and from wealthier areas of the country, would much rather allow the Bush-era tax rates to be extended for everyone who earns less than $1 million. Under the Obama plan, there would be a one-year extension of all the Bush-era tax cuts for the first $250,000 of each household’s income. A family’s remaining income above that $250,000 threshold would be taxed at a higher rate.

Democrats believe they will easily have the votes to beat back an extension of all the Bush-era tax cuts.

“I don’t believe there will be many, if any, Democratic senators voting to extend the Bush tax cuts,” said Senate Majority Whip Dick Durbin after a Democratic leadership meeting with Obama in the Oval Office.

Lieberman said he'll vote against the Republican plan as well.

"I think we can do better than that this year," he said in a statement, referring to the Obama and GOP plans.

While nearly every Senate Democrat will support the president’s plan, some Democratic lawmakers appear to be threatening to join Lieberman.

Asked twice whether he would vote to support Obama’s proposal, Manchin would only say, “We’ll be looking at it very strongly.”

Similarly, Sen. Bill Nelson (D-Fla.), who faces a tough reelection bid this fall, would only say Wednesday he was about to discuss his tax views with Reid and that his “preference” is to set that level at $1 million.

“I’ll talk to you when I’m ready to vote,” Nelson said.

Sens. Ben Nelson (D-Neb.) and Jim Webb (D-Va.) also voted in 2010 against allowing Bush-era rates to expire above the $250,000 level. Nelson was non-committal on the Obama plan when asked about it earlier this week.

Webb doesn’t believe that taxes should be increased on ordinary income, and has instead called for higher tax rates on capital gains and dividends.

“His position remains the same,” an aide said.

A spokeswoman for Sen. Jon Tester (D-Mont.) said her boss was still “determining the best proposal for Montana families and small businesses.”

“Jon’s priority is to cut government spending and cut special tax breaks that benefit the very wealthy, but he will not support any plan that results in higher taxes for middle-class families,” said Tester spokeswoman Andrea Helling.

Still, Obama’s team has succeeded in limiting some defections already, after dispatching top administration officials to Capitol Hill on Tuesday. They argued that 97 percent of small businesses would benefit from the plan.

After saying he “disagreed with the president” on the $250,000 level earlier this week and preferred keeping it at a higher threshold, Sen. Bob Menendez (D-N.J.) now plans to vote in favor of the president’s plan. He says he’d rather support the Obama plan than what the GOP is proposing.